60 lines
1.5 KiB
C++
60 lines
1.5 KiB
C++
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// Copyright (c) 2013, Facebook, Inc. All rights reserved.
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// This source code is licensed under the BSD-style license found in the
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// LICENSE file in the root directory of this source tree. An additional grant
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// of patent rights can be found in the PATENTS file in the same directory.
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//
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#include <string>
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#include <algorithm>
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#include "util/file_util.h"
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#include "rocksdb/env.h"
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#include "db/filename.h"
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namespace rocksdb {
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// Utility function to copy a file up to a specified length
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Status CopyFile(Env* env, const std::string& source,
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const std::string& destination, uint64_t size) {
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const EnvOptions soptions;
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unique_ptr<SequentialFile> srcfile;
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Status s;
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s = env->NewSequentialFile(source, &srcfile, soptions);
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unique_ptr<WritableFile> destfile;
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if (s.ok()) {
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s = env->NewWritableFile(destination, &destfile, soptions);
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} else {
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return s;
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}
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if (size == 0) {
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// default argument means copy everything
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if (s.ok()) {
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s = env->GetFileSize(source, &size);
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} else {
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return s;
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}
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}
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char buffer[4096];
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Slice slice;
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while (size > 0) {
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uint64_t bytes_to_read =
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std::min(static_cast<uint64_t>(sizeof(buffer)), size);
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if (s.ok()) {
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s = srcfile->Read(bytes_to_read, &slice, buffer);
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}
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if (s.ok()) {
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if (slice.size() == 0) {
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return Status::Corruption("file too small");
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}
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s = destfile->Append(slice);
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}
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if (!s.ok()) {
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return s;
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}
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size -= slice.size();
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}
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return Status::OK();
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}
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} // namespace rocksdb
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